package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Follow;
import com.hmdp.mapper.FollowMapper;
import com.hmdp.service.IFollowService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.UserHolder;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author <a href="https://gitee.com/hebei-dynasty-competition">搜一码赛</a>
 */
@Service
public class FollowServiceImpl extends ServiceImpl<FollowMapper, Follow> implements IFollowService {
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private UserServiceImpl userService;
    /**
     * 关注和取消关注
     */
    @Override
    public Result follow(Long followUserId, Boolean isFollow) {
        //获取当前登录用户的id
        Long userId = UserHolder.getUser().getId();
        String key="follows:"+userId;
        //判断是关注还是取消关注
        if (isFollow){
            //关注,新增数据
            Follow follow = new Follow();
            follow.setUserId(userId);
            follow.setFollowUserId(followUserId);
            boolean isSucess = save(follow);
            if(isSucess){
                //把关注的用户存入Redis的set集合中
                stringRedisTemplate.opsForSet().add(key,followUserId.toString());
            }
        }else {
            //取消关注,删除数据
            boolean isSucess = remove(new QueryWrapper<Follow>()
                    .eq("user_id", userId).eq("follow_user_id", followUserId));
            if (isSucess){
                //从Redis中移除
                stringRedisTemplate.opsForSet().remove(key,followUserId.toString());
            }
        }
        return Result.ok();
    }

    /**
     *     判断是否关注
     */
    @Override
    public Result IsFollow(Long followUserId) {
        //获取当前登录用户的id
        Long userId = UserHolder.getUser().getId();
        //查询是否关注了
        Integer count = query().eq("user_id", userId).eq("follow_user_id", followUserId).count();
        return Result.ok(count>0);
    }

    /**
     * 查询共同关注
     * @param id
     */
    @Override
    public Result followCommons(Long id) {
        //1.获取当前用户
        Long userId=UserHolder.getUser().getId();
        String key="follows:"+userId;
        String key2="follows:"+id;
        //2.求交集
        Set<String> intersect = stringRedisTemplate.opsForSet().intersect(key, key2);
        if(intersect==null|| intersect.isEmpty()){
            //无交集
            return Result.ok(Collections.emptyList());
        }
        //3.解析id集合
        List<Long> ids = intersect.stream().map(Long::valueOf).collect(Collectors.toList());
        //4.查询用户
        List<UserDTO> users = userService.listByIds(ids)
                .stream()
                .map(user -> BeanUtil.copyProperties(user, UserDTO.class))
                .collect(Collectors.toList());
        return Result.ok(users);
    }
}
